webadmin: Change default doc path.

The standart directory for docs is - /usr/share/doc.
We need to deploy docs content there as well.

Change-Id: I6343b83cfae3207235b85e41fd66163b0cf3a1e8
Signed-off-by: Kiril Nesenko <knesenko@redhat.com>
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=882284